Color grading apparatus



Dec. 23, 1941. w. o. BENNiNG COLOR GRADING APPARATUS Filed June l0, 1940 2 She'ets-Sheet l Dec. 23, 1941. w. Q BENNING 2,267,319

COLOR GRADING APPARATUS c: 2:1372? Jou-rc e f5 WZ I--l I'IIIIIII llljal'bllfr Mlmim/ INVENTOR.

ATTORNEY.

Patented Dec. 23, 1'941 OFFICE 2,267,319 coLoa GnAnmG APrAaATUs Wilbert Orville Benning. Los Angeles, Calif. Application June 1o, 1940, sei-lai No. 339,626 (ci. sii-i4) l Claim.

My invention relates to improvements in color grading apparatus and more particularlyto a light sensitive device for measuring, sorting or grading articles according to their dierences in intensity of color ox" shade, where such articles are required to be of a uniformity of shade of a this specification, Fig. 1 is a. top plan with a portion of the cover broken away; Fig. 2 is a side elevation with a portion of the cover and base broken away; Fig. 3 is a section taken on the line certain color, as compared with a standard. In

the following disclosure of my invention I have shown and described my improvements as applied to tiles but it will be understood that it is equally applicable for measuring, sorting or grading other articles according to their differences in intensity of color or shade, within the spirit of the invention. y

Among the objects of my invention is the production of an apparatus oi its kind by which comparisons of shade can be made rapidly and in which adjustments can be easily made and are simple in construction. Another object is the production of apparatus by which persons entirely unskilled in the matching' of colors or in handling or operating mechanical or electrical devices can easily and eillciently operate the device. Another object of this invention is greater simplicity of the component parts and the absence of optical systems, lenses, prisms and mirrors, as used between the initial light source and the tiles or other articles to be measured or compared. Another object is the housing of the light sensitive cells in such a way that no extraneous light can inuence their action or balance, other than from the tiles or articles under measurement or comparison. Another object is the production of an apparatus for the grading of shades of color wherein the human element of error is entirely eliminated when once the allowable tolerance has been set. Another object is an apparatus in which the tiles or articles to be graded can be fed to their position below the opening or window below the light sensitive cells, manually or by slight modification, mechanically and automatically. Another object is to provide a simple, accurate and dependable color or shade matching device, wherein a single source of substantially white light is utilized whereby any uctuation in line voltage will aiiect both lightsensitive cells equally. A still further object is to provide an apparatus which with slight modiiication is readily adaptable to comparison of oils or other liquids as to their clarity, or intensity of color, such as paints.

To these ends my invention comprises the fea- 3--3 of Fig. 2; Fig. 4 is a plan showing the arrangement of the instruments of the control panel; and Fig. 5 is a schematic diagram ,of one v type of electric circuit employed.

In the following description it willbe/understood that changes can be made in the form, size, proportions and other details of construction, in4 order to adapt the invention to the individual requirements of the article or articles to be graded or sorted without sacrificing any of the advantages of the device.

In the drawings, A indicates the outside casing cover which is intended to contain the control panel I0 (see Fig. 4) and also the Ventilating louvers I I and a horizontal light baille I2 below the louvers. The cover A telescopes over a base I3 which supports the step down transformer Il and the pair of light sensitive cells I5 and I6 together with the transverse iilter slide I1. These light sensitive cells are arranged transversely in horizontal alignment immediately above the filter slide. base I3 serves to support the light cells. Agongitudinal vertical fence or partition I9 is supported upon the base I3 between the lamp 25 and the light sensitive cells and divides the incident light from the lamp 25 (see Fig. 2) into two beams. The base I3 also contains two openings or windows 20 and 2| arranged side by side beneath one of which is placed a longitudinal and horizontal slide 22 and beneath the other the slide 23, said slides being adjacent to each other and parallel and being so shaped and adapted as to guide tiles such as B and C and any other articles of any suitable shape to be sorted and graded through the device, exposed to the iniiuence of the light sensitive cells. 'Ihese slides 22 and 23 in addition to guiding the tiles or articles longitudinally beneath the windows 20 and 2| exclude tures of construction and combinations of parts hereinafter described and claimed.

In the accompanying drawings forming part of extraneous light.

Arranged in advance of the light sensitive cells and above theplane of the tiles in the slides is a ventilated lamp housing D, which contains a single lens 24 in its lower end and a single source of light which may be a single, concentrated i'ilament prefocused incandescent lamp such as 25, arranged to direct its rays through the lens and on either side of the fence I9 down upon the surfaces of a pair of the tiles which are supported face upward in the guides or slides 22 and 23.

A transverse partition 50 interposed between the A suitable frame I8 mounted upon the automatic.

said c lls from the lamp within said housing. In ing the device to determine whether one i tile or article differs from another in shade or color, two articles or tiles of the same shade and color are used, one placed beneath each window, and the instrument or device balanced electrically. When once balancedone tile or article after another may be run through one of the slides without'any other adiustment being made, all other operations being automatic or semi-h The other tile or article in the opposite slide remains permanently and is used as a standard" with which the unknown tiles or articles must be balanced to determine even shadei' or color.

Suitable filters such as 28 may be placed in the filter slide I1, one beneath each light sensitive cell, to narrow the frequency band to substantially the same band as the articles to be sorted or graded. 'Iwo power relays 21 and 21' (see Fig. 5) are included in the photocell circuit and coupled with a sensitive galvanometer relay 29, the latter being placed on the service panel l of cover A within full view of the operator and by which the latter can determine the closeness with which the shade or color of each unknown tile or article matches the standard tile or article used in the apparatus. As the unknown tiles or articles pass under the corresponding window and are compared or measured, the power relay 21 or 21' immediately responds to influence the diversionl of the article into its proper place according to its shade or grading, the diversion apparatus with which the power relay co-operates not being shown.

All parts within the casing are coated with non-reflecting black pigment, in order that any light rays that may be reected on them will be absorbed and not reilected again, so as to impinge upon the light sensitive cells of the device.

Thus this device utilizes a plurality of light sensitive cells I5 and I6, a single light source representerdgby the lamp 25 to illuminate the tiles or articles to be graded or measured, a means of balancing the electric system according to the material or article to be graded or measured, and also a means of modifying the sensitivity to any degree of tolerance.

1n this invention the measurement of direct reilection of light/ from surfaces of the tiles to be graded or measured is avoided, by allowing the light beams to fall on each tile at such an angle that the directly renected light does not impinge upon the light sensitive cells but is reflected upon the black light absorbing walls of the interior of the ease.

In general, to operate the apparatus, both the A. C'. switch 30 and the battery switches 32, 45, 46 and 41 are turned on. Then identical samples or standards represented for illustration by similar tiles B and C are placed one beneath each of the windows 20 and 2| by -sliding through the slides 22 and 23. The electric circuit is then balanced by the adjustment of the control 43, until the indicating -arm on the sensitive galvanometer relay 29 is in the center or neutral position. The proper illter 26 for the particular shade of tile to be graded is next placed in the filter slide I1. Articles to be measured and sorted are then fed along the slide 23 and either compared orv matched with the standard tile which is left stationary as a sample below window 20 above slide 22. The electrical circuit is cut by means :ammalav of a switch 32 until the tile or article is in proper position for measuring at which time the circuit is closed. Upon closing the circuit, the sample tile below window 2| is automatically measured. Suitable sorting means may be cooperatively associated with'the power relays or solenoids (not shown) 'for sorting according to the measurements already made. As shown indicating lamps 33 and 34 (see Fig. 5) are coupled into the cir-l cuit which is controlled by the relays 21 and 21' for aiding the operation by visual indication.

It is possilge to utilize the scale on milliammeter 34 as a direct indicator of light intensities, or a specially designed or calibrated scale in which case the galvanometer is merely used to v indicate when the circuit has reached a certainvalue, such as a balance or zero.

In Fig. 5, 3l indicates the main switch which disconnects the entire apparatus from the A. C. supply. I4 represents the step down transformer. the secondary winding of whichsupplies the proper illament voltage for the amplifier vacuum tube 35. Referring to the measuring, amplifying and indicating systems, I5 and I6 are the two light sensitive cells, which derive their potential from the battery indicated as 31, which latter is coupled to the input of vacuum tube 39, which4 is used as an ampliiler, whose plate circuit feeds through an indicating device represented by 33; and also through a sensitive relay 29 which may operate suitable power relays rep-` resented by 21 and 21', from which any signal deergized by battery 40. Variable resistance 4I acts l as a balance for the sensitive relay 29. Variable resistance 42 acts as a sensitive control by shunting more or less current around relay 29. Variable resistance 43 regulates the' grid bias of amplifier tube 36. Variable resistance 44 by varying the potential across the light sensitive tubes i5 and I5 sets the pointer of the'indicating device 33 to a reference point. As varying intensities of light strike the light sensitive cells l5 and I6, the current varies, swinging the grid of tube`35 more or less negative, which in turn increases or decreases the plate current of tube 38, which plate current actuates relay 29, also in-v dicating device 38, to the left or right, whichever variation is indicated, energizing one or the other of the solenoids of'power relays 21 and 21'. Switches 32, 45, 45 and 41 control the current from the batteries leading to the several elements.

'I'he manner of operating this invention is susceptible of wide variation, and while I have described a method of making measurements, it is to be understood that I am in nowise conilned to this use alone or tothe particular construction above described within the spirit of the invention and the scope of the claim following.

I claim:

A color and shade comparison apparatus, comprising, a cabinet having a base provided with a transverse pair of window openings, a pair of longitudinally disposed slides extending beyond the opposite ends of said cabinet to guide tiles in registration one below each window opening and having solid floors shielding the openings from extraneous light when tiles are removed, a source of light in the cabinet directed longitudinally down upon the tiles exposed through said window openings, a central longitudinal beam vlight which is reflected by the tile exposed through one window opening upon the companion light sensitive cell from impinging upon the opl0 posite light sensitive cell, a frame shielding saidl light sensitive cells from extraneous light, andv r having lter receiving slides disposed beneath the cells and in the paths of the reflected light beams, and a differentiating bridge circuit connected with said cells containing means'for indicating.

variations in electric current due to variations in the color of light impressed upon said cells. l

WILBERT ORVILL BENNING. 

